From 5908cdc85eb30f8d07f2cb11d4a62334d7229048 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Sat, 9 Jan 2010 20:53:14 +0100 Subject: [PATCH] list: Introduce list_rotate_left() Bring a new list_rotate_left() helper that rotates a list to the left. This is useful for codes that need to round roubin elements which queue priority increases from tail to head. Signed-off-by: Frederic Weisbecker Acked-by: Peter Zijlstra Cc: Paul Mackerras Cc: Ingo Molnar Cc: Arnaldo Carvalho de Melo --- include/linux/list.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/include/linux/list.h b/include/linux/list.h index 969f6e92d089..5d9c6558e8ab 100644 --- a/include/linux/list.h +++ b/include/linux/list.h @@ -205,6 +205,20 @@ static inline int list_empty_careful(const struct list_head *head) return (next == head) && (next == head->prev); } +/** + * list_rotate_left - rotate the list to the left + * @head: the head of the list + */ +static inline void list_rotate_left(struct list_head *head) +{ + struct list_head *first; + + if (!list_empty(head)) { + first = head->next; + list_move_tail(first, head); + } +} + /** * list_is_singular - tests whether a list has just one entry. * @head: the list to test. -- 2.20.1